Canon HV20 HDV Camcorder Reviewby John NeelyPublished on Mar 26, 2007 5:00 PM
|
Advertisement
|
||||||||||
Compression (7.0)
The Canon HV20 (Review, Specs, Recent News, $903) uses HDV compression, a very efficient MPEG-2 codec with a fixed data rate of 25Mbps, identical to the data rate of standard definition DV compression. HDV excels in capturing stunningly high-resolution video, but it is inferior to DV in terms of rendering motion realistically, due to its dependence on interframe compression. This means that at 1080i, only one in fifteen frames is a full-frame picture, while the intervening frames are compressed in relation to each full I frame. Interframe compression is much more efficient than intraframe compression, and allows HDV to squeeze a full 1920 x 1080 picture into a 25Mbps stream, recordable to inexpensive MiniDV tapes. DV uses intraframe compression, so each frame is a fully independent picture, allowing much better motion capture. DV also uses a superior 4:1:1 color space while HDV encodes via a truncated 4:2:0 color space.
The inherent weaknesses of HDV have led many networks to deem the format sub-standard for broadcast, but it is still the best high definition format available on the consumer camcorder market. Most consumers find the stunning resolution of HDV trumps the superior motion handling of DV. A professionally lit HDV interview (or any HDV shot without too much detail or motion) can look nearly as good as footage shot in a professional HD format on a $20,000 camera. AVCHD, a new HD format that uses H.264 compression was introduced in 2006 and compresses video even more aggressively than HDV. Our tests of Canon's UX1 (Review, Specs, Recent News, $729.95) and SR1 (Review, Specs, Recent News, $1119.99) last fall show that while AVCHD video is very sharp, it suffers from grain and artifacts much more than HDV compression. The wildcard in the consumer high definition arena is a new MPEG-2 format developed by JVC, the MPEG Transfer Stream codec, which appears for the first time in the Everio HD7 (Review, Specs, Recent News, $1529). MPEG Transport Stream compresses video at up to 30Mbps, and may rival or even outclass HDV compression.
Media (6.0)
Like other HDV camcorders, the Canon HV20 records to MiniDV cassettes, the same inexpensive and widely available format used by standard definition DV camcorders. MiniDV cassettes have a run time of 60 minutes in SP mode, but can hold up to 90 minutes of more compressed LP video. Unlike the DVD, memory card, and HDD formats, MiniDV tapes are linear media so moving clips to a PC from tape is a real-time process. For anyone serious about the quality of his or her video, HDV recorded to MiniDV cassette remains the best consumer HD option available. To date, consumer non-linear video formats do not support the highest-quality video compression codices for high definition (HDV) and standard definition (DV).
Editing (7.0)
The Canon HV20 records both HDV and standard definition DV video to MiniDV tapes, and both formats are now broadly supported by consumer and professional NLEs (non-linear editors) like Apple iMovie and Final Cut Pro, Avid Liquid and DV Express Pro, and Adobe Premiere. Transferring footage to a PC or Mac for editing is done via the included IEEE 1394 (otherwise known as FireWire, and branded as "i.LINK" by Sony) cable, so your PC will need an appropriate adapter. All Macs are IEEE 1394 compatible.
Due to its higher compression rate, working with HDV footage is much more processor-intensive than DV, but any newer computer with at least 512MB of installed RAM (and preferably 1GB) running an HDV-compatible NLE should be able to handle 1080i footage.
|
Advertisement
|